- #1

MathematicalPhysicist

Gold Member

- 4,699

- 369

can a computer (determnistic) create chaos (disorder)? if it can be done how can it be done?

You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter MathematicalPhysicist
- Start date

- #1

MathematicalPhysicist

Gold Member

- 4,699

- 369

can a computer (determnistic) create chaos (disorder)? if it can be done how can it be done?

- #2

Jonathan

- 365

- 0

- #3

MisterBig

- 27

- 0

Any random data generated by a computer is known as pseudorandom, data that has the characteristics of random data but that was created (and can be exactly recreated by) an algorithm.

The computer could sample information from the environment (CPU temperature or fan speed would be fairly easy to get) and that would be truly random. For it to be useable you’d probably need to process it a bit first though.

- #4

Jonathan

- 365

- 0

I've changed my mind, I agree with MisterBig, it's impossible for a computer to have random output without random input. True randomness is impossible to recreate. I don't know how I explicitly stated that a computer will come up with the same anwser in a "chaotic" equation if the inputs are EXACTLY the same without seeing the flaw in my logic.

- #5

HallsofIvy

Science Advisor

Homework Helper

- 43,021

- 970

The mathematical theory of chaos (taking it's name from Yorke's paper "Period Three Implies Chaos") is deterministic, not random.

In a sense it's the opposite of the "Central Limit Theorem".

We've all seen the demonstration where if you drop a large number of marbles (or shot) onto a grid so that each one goes left or right a number of times and then the "pile" comes right up to a pre-drawn curve. In other words, a sequence of purely random events can give a pre-determined result.

"Chaos" (again, technical, mathematical meaning) refers to a purely deterministic process that is so sensitive to "initial conditions" that it is impossible to predict the results.

Simple example: given x

One can show that two intial values arbitrarily close together can rapidly give completely unrelated values.

- #6

Jonathan

- 365

- 0

That's what I meant, but I now question how chaotic something really is if it is repeatable. Now I've contradicted myself ... asprin! ... asprin! ...

- #7

chroot

Staff Emeritus

Science Advisor

Gold Member

- 10,275

- 40

- Warren

- #8

MathematicalPhysicist

Gold Member

- 4,699

- 369

then let's rephrase the question can computer create randomness?

- #9

wimms

- 496

- 0

Actually, it wouldn't hurt to define 'chaos' or 'randomness'. I personally don't think 'true randomness' is possible unless acausal is involved, in principle.

Of course computer can create chaos. See http://www.isp.nwu.edu/~rocky/Pendulum/QuintuplePendulum.html [Broken]

It can compute trajectory that is chaotic. But there's no way to determine what caused it given trajectory alone.

How do you define 'randomness'? There are many definitions. For eg. infinite period before repitition begins. Its enough to calculate Pi infinitely to produce randomness. For eg. maximum information density. Then generate white noise.

Of course computer can create chaos. See http://www.isp.nwu.edu/~rocky/Pendulum/QuintuplePendulum.html [Broken]

It can compute trajectory that is chaotic. But there's no way to determine what caused it given trajectory alone.

How do you define 'randomness'? There are many definitions. For eg. infinite period before repitition begins. Its enough to calculate Pi infinitely to produce randomness. For eg. maximum information density. Then generate white noise.

Last edited by a moderator:

- #10

Joy Division

- 46

- 0

- #11

chroot

Staff Emeritus

Science Advisor

Gold Member

- 10,275

- 40

- Warren

- #12

Tyger

- 398

- 0

- #13

Loren Booda

- 3,119

- 4

- #14

jcsd

Science Advisor

Gold Member

- 2,101

- 12

Modern day computers cannot generate true randomness, though I beleivethere is a device (maybe it's still in the developmental stage) which uses the probabiltistic nature of QM to generate truly random numbers,

- #15

wimms

- 496

- 0

To get truly random numbers, many comps are using human keyboard input as initial conditions in chaotic algoritm. Like every time you type something, comp measures time between keystrokes and randomness depends on that heavily. Thats about simplest way to get randomness form environment.

In addition, thermal conditions affect frequency of operation abit, and if computer has 2 independant clocks, minute differences between them are dependant on environment alone. The only task is to amplify these tiny changes by chaotic algoritm into randomness.

- #16

Duncan

- 9

- 0

The answer to the question, can computers create random numbers? Of course depends on the inputs to create the numbers. If no input(ie a pseudo random number generator) then no*. If the input is random then yes. Intel therefore have created the Intel Random Number Generator on their chips to create what should be truly random numbers.

http://apps.intel.com/scripts-util/download.asp?url=/design/security/rng/techbrief.pdf&title=The+Intel+Random+Number+Generator&fullpg=3&site=Developer [Broken]

Very useful if you are encrypting data.

Some encryption products like PGP get inputs from keyboard and mouse use. These provide non-deterministic input to help create random numbers.

Duncan

* If you define random numbers as being non-deterministic.

Last edited by a moderator:

Share:

- Replies
- 12

- Views
- 547

- Last Post

- Replies
- 8

- Views
- 2K

- Last Post

- Replies
- 1

- Views
- 900

- Last Post

- Replies
- 15

- Views
- 4K

- Last Post

- Replies
- 5

- Views
- 3K

- Last Post

- Replies
- 1

- Views
- 1K

- Replies
- 10

- Views
- 1K

- Last Post

- Replies
- 1

- Views
- 970

- Replies
- 5

- Views
- 2K

- Last Post

- Replies
- 6

- Views
- 911